1. Field of the Invention
The present invention relates to a method for operating an internal combustion engine, especially a quality-controlled internal combustion engine, and also to a computer program product for executing the method and a control device for an internal combustion engine.
2. Description of the Related Art
The demands on modern internal combustion engines, particularly those used in vehicles, rise continuously, conditioned upon both legal boundary conditions with respect to admissible emission limits and increased expectational attitudes of end users with respect to travel comfort, smooth running and consumption. One fundamental approach to fulfilling these requirements is an exact control of fuel combustion. This takes place, for instance, in so-called quality-controlled internal combustion engines, which work according to the Diesel combustion method or a lean Otto combustion method, via a targeted, load-dependent control of the composition of the cylinder charge of fresh air and recirculated exhaust gas, as well as the injection quantity and the injection time of various types of fuel injections, which are set down in changing injection patterns.
One further growing requirement relates to the accuracy with which the internal combustion engine provides the requested torque over all conditions of load and environment. Special new vehicle power train types, which have hybrid drives and/or automatic transmissions having a large number of speeds set very high requirements on accuracy. The accuracy of the torque is determined mainly by the accuracy at which the engine efficiency is able to be ascertained, and by the accuracy at which fuel injection quantities are metered in. In this context, in particular, tolerances of the injection quantities in multiple injections, having high variability of the injection patterns and injection intervals, may become so great that the torque accuracies required of the abovementioned drive concepts can no longer be fulfilled.